In the last months, our 3D guy, Pekka Laurila, has been doing some 3D models of different aspects of Aalto-1. Here you go:
Aalto-1 passed the Preliminary Design Review earlier this autumn with a great help and wisdom from our reviewers, which will undoubtedly help us in the future. Also, we hosted a payload PDR, where payload teams cleared lot of previously unanswered questions.
Our team is now heading for Christmas holidays, eager to return after New Year’s eve to tackle the next challenges.
On Easter holidays we started to build Aalto-1’s next mock-up model. First we went to the Design Factory with some aluminum metal sheet. First step was to find correct way to bend aluminum in certain accuracy, and at the end of the day we managed to make accurate model of the frame structure. Only one corner is just little bit out of shape. Next step was to order some 3D printed parts and wait for 10 days. During the waiting time we went back to the Design Factory and sawed some PCB board mock-ups. When the 3D-parts arrived we started assembling the model. So with all parts in right place the satellites outer dimensions were just 340,5x100x100 (mm), quite accurately what the specifications say. When we were building the model we found out, that some of the joining methods and placings will not work as planned, so we must re-think some of them in the near future.
The 8th IAA Symposium was held in Berlin in April. The event consisted of lectures, social events and companies presenting products and services. The Aalto-1 ADACS (Attitude Determination and Control System) guys Tuomas and Hannu had a chance to visit this interesting city and the conference.
In the first evening there was a reception event. There we met Tom who offered us a chance to visit the Technische Universität Berlin (TU Berlin) the next day.
TU Berlin is one of the largest technical universities in Germany where also the famous Wernher von Braun used to study . Maria and Anssi from our project were also visiting Berlin and came along. Here we are at the roof of the aerospace department. The antenna in the background is used for satellite communications.
From the left: Tom, Anssi, Maria, Hannu, Tuomas
Tom showed us also their mission control room. Let’s hope we have something similar someday!
One of the coolest things during the conference was definitely a live demonstration of satellite attitude control. Once a satellite was in communication distance it sent us live video footage via a ground station to a TV screen. It was tumbling quite badly and we tried to stabilize it by sending manual control commands from a laptop back to the satellite. Not an easy thing to do with lag due to the vast distance to the satellite! Finally we got it stabilized and saw some magnificent views of the Mediterranean before it flew out of the communication antenna’s reach. Not the best way to control a satellite but definitely the most fun!
Although we had learned a lot and met many interesting people, there was still a problem: we were still missing an ADACS from our satellite. So we met once again with Tom as we had heard that his company, Berlin Space Technologies, is designing one for Nanosatellites. Looks like we can do some further co-operation with them in the future. Let’s see what happens!
Pizza, modeling clay and satellite mock-up building!
On Friday 18.3.2011 the Aalto-1 team got together in Aalto University’s space technology laboratory to build a live-sized mock-up of the Aalto-1 satellite. The goal of the session was to assemble a mock-up of the Aalto-1 satellite, to have fun and to engage and motivate the team. During a long afternoon the team enjoyed some pizza and snacks while assembling the satellite’s aluminum frame and various subsystems, from the antennas to the ADACS-module and spectrometer. The end result was a happy team and a fine looking satellite mock-up!
The mock-up satellite consists of an aluminum frame that is close to the actual size of the future flight model (10x10x30 cm). The different subsystems and components inside and on the satellite were modeled using circuit boards, different plastic and rubber bits, and even modeling clay, pieces of measuring tape and a toilet paper roll. The locations of the subsystems are roughly comparable to those of the future flight model.
In the assembly process the team got a chance to make a proof of concept of the deployment of the UHF/VHF antennas (see photos further down). The antennas on the real satellite (4 antennas, 2 for each frequency band) are most likely going to be made up of springy metallic strands, not unlike a tape measure strand. The antennas were therefore simulated by using 50 cm long pieces of metallic measuring tape. The mock-up antennas were curled up in a tight roll and were held in that position by cotton string to simulate the launch arrangement. In a real satellite the string is usually made up of nylon that is cut by melting it with a heat resistor when the antennas are deployed. The team simulated the deployment by burning the cotton string with a cigarette lighter. Crude but effective! The cotton strings were cut as expected and the antennas deployed, proving the concept’s validity.
Overall, the session succeeded very well. The team now has a platform with which different mechanical solutions can be prototyped and tested. A proper physical manifestation of the satellite also makes the goal of designing and building a real satellite much more concrete.
Here are some photos of the session:
We started off with a short team meeting and recap of each member’s current work status.
After this the prototyping itself was started. There were pieces of aluminum profile to be used as the satellite’s frame…
…and miscellaneous screws, plastic parts, modeling clay and other thingamajigs for the subsystems.
FMI (Finnish Meteorological Institute) had provided some solar cell mock-ups to be used as models for the ones put on the satellite mock-up.
The team started off by getting familiar with the available building materials …and the snacks.
The circuit boards for the satellite’s subsystems were modeled using generic circuit boards that were cut into a shape fitting inside the 10×10 cm cross section of a cubesat.
The frame starting to take shape…
The ever vigilant project manager observes the progress of on board computer testing.
Back to work! Drilling a hole to a part of the aluminum frame.
Deploying one of the antennas as proof of concept. The cotton string holding the tape curled up is cut by burning it with a lighter.
Three competed subsystem mock-ups awaiting integration into the satellite.
Putting the subsystems’ modules togeter.
Applying finishing touches.
Ground station development has made huge progress. We have made a list of needed components for a working VHF/UHF ground station that will be able to both transmit and receive on these amateur frequency bands. Also automatic satellite tracking will be possible. The first parts will arrive this week if everything goes according to the plan. The total price for a ground station will be around 5000€, the most expensive parts being the radio, (ICOM IC-910H, 1400€) and the rotor (BigRAS, 1600€).
The ground station will be located on the fourth floor of the Department of Radio Science and Engineering. The roof has housed a ground station before: On the roof we could find an old mast with rusty motors, 2m crossed Yagi, 70cm helix and a linear Yagi for some higher frequency.
The operation of the former ground station is in a shroud of mystery. The story tells that the former Laboratory of Space Technology used the antennas to receive telemetry data from a weather satellite during a laboratory course in the beginning of 90’s. The ground station was also used with P3D amateur satellite that was launched in 2000.
We have decided to join the GENSO – a network of HAM and university satellite ground stations. GENSO connects separate ground stations by relaying recorded audio files from a radio station to another. This allows every cubesat team to hear and control their satellite regardless of the satellites position on the sky. Future development include the S-band reception and research on the software defined radio.
The digital data can be demodulated by connecting the receiver standard PC soundcard’s microphone line and demodulating it with a suitable program. Fldigi is one of such software packages. Youtube video and a laptop speaker and microphone seem to offer high enough audio quality to enable correct demodulation of the simplest modulations.
You can try Fldigi out while waiting for more news: http://www.w1hkj.com/Fldigi.html
Gpreditc: multi-platform satellite tracker http://gpredict.oz9aec.net/
Orbitron: satellite tracker for Windows http://www.stoff.pl/
Space: the final frontier. These are the adventures of the satellite Aalto-1 and its crew to explore near Earth space and to research the blue planet, to seek out solutions for difficult engineering problems and to boldly reach for the stars.
Despite the fact that mankind has been sending probes and satellites to space for over 50 years, it still remains a tough challenge to beat. For government organizations and big businesses with billions to spend, challenges can be overcome, but for smaller organizations space tech is still expensive and the launch prices reaching thousands of euro’s / dollars per kilo are still a burden.
However, during the last few years a development of CubeSat standard has dropped the price of the components and lowered the development hurdles for educational institutes to build their own satellites. Means alone are not enough for us to build a satellite, but thanks to the cooperation with our Finnish partners Finnish Meteorological Institute, VTT Technical Research Center Finland and Universities of Helsinki and Turku, we also have a reason to build the satellite. FMIs electrostatic plasma brake, UTUs and UHs radiation monitor and VTT’s Fabry-Perot spectrometer all can benefit from testing in space, thus creating a need for a satellite.
Aalto-1 is an ambitious CubeSat mission featuring multiple scientific instruments, advanced three-axis stabilized attitude control and high-bandwidth S-band microwave downlink. Our satellite will be launched to a sun synchronous polar orbit at around 700km altitude. What are CubeSats, attitude controls, polar orbits and so forth? What are the thousands of problems we face if we want to send operational instruments to space and how do we overcome them? By following this blog, you can learn answers to these and many other questions and keep up to date about the progress of our voyage to reach for the space. You are also welcome to send your own questions to this blog and we will try to answer them.
Welcome to the Aalto-1 blog. This place is dedicated to talk about the Aalto-1 project, the first Finnish nanosatellite.The goal of this blog is to share with the world and specially with the community of Aalto University the progress of the project. If you are not familiar with the project we highly recommend you to visit the official web, and if you feel adventurous, if sometimes you look to the sky and you think: what is there?, or if you just want to help in a tricky project that requires high engineering deployment and implies to work with space technology, a multicultural environment and much more, please don’t hesitate! join us!